Oncolytic virotherapy (cancer virotherapy) is a therapy in which a virus is allowed to infect cancer cells, and proliferate in cancer tissues to destroy and kill the cancer tissues by utilizing oncolytic property of the virus. Clinical studies are being conducted by using adenovirus and herpes simplex virus, which are DNA viruses, against brain tumor or breast cancer, and results showing safety and efficacy thereof are being reported.
Coxsackievirus group B type 3 (CVB3) (Non-patent documents 1 to 3) has a single strand plus-strand RNA genome, and proliferates only in the cytoplasm, and thus it hardly possibly introduce mutation into a host cell genome. Therefore, it is thought that it can be comparatively safely used in oncolytic virotherapy. Moreover, CVB3 is a common virus, and even if it infects, infection is limited to inapparent infection in many cases. However, there are reports concerning relevance thereof with aseptic meningitis, viral myocarditis, and pancreatitis. Marked oncolytic property of CVB3 against human non-small cell lung cancer has also been reported (Non-patent document 4).
As one of viruses of which application to the oncolytic virotherapy is expected, coxsackievirus group A type 21 (CVA21) is known (Patent document 1), and it has been reported that the virus was proliferated in a tissue-specific manner by incorporating miRNA into the virus genome (Non-patent document 5).